The present invention generally relates to a branch connector which is provided in an intermediate portion of a wire harness for connecting electric wiring parts and so on for use in motorcars and which connects together electric wires in the wire harness so as to form a branch circuit, and more particularly, to a branch connector to be used when the wire harness has been formed of an FPC (flexible printed circuit).
Conventionally, this type of wire harness includes a main line 1 having many wires being bundled together, a branch line 2 which is branched in accordance with the mounting position of each of the battery powered car parts from an intermediate place of the main line 1, and a terminal 3 which is connected with the tip end of each branch wire, with these terminals being connected with each of a plurality of electric wiring parts (not shown), as shown in FIG. 22.
An operation of branching a branch line 2 from the desired position along the main line 1 and an operation of mounting the proper type of terminal 3 to the tip end of the branch line 2 must be carried out each time for each of the electric wiring parts. Accordingly, operational troubles often occur and, parts management also becomes complicated.
Furthermore, as the number of manual operations is large, the connection becomes uncertain. Troubles such as connection errors, disconnection, shorts, and so on are likely to be caused, thus resulting in inspection/repairs which causes problems.
In order to remove the above described disadvantages, Japanese Utility Model Publication No. 61-38350, Japanese Patent Application Publication No. 61-45575 and so on are proposed, where branch portions of the branch lines from the wire harness main line are concentrated in one location to simplify the wiring system so that the connecting operations may be easily effected quickly and positively.
In either of the apparatuses disclosed in the above described publications, a connector is respectively mounted on many electric wire groups taken out from one wire harness and connected with each other. Many connectors are accommodated in parallel relation within a joint block. Through a pressure contact terminal (Japanese Patent Application Publication No. 61-45575) or a bus bar (Japanese Utility Model Publication No. 61-38350), mounted on the case of the joint block, the above described connector is connected with the selected electric wire of the other wire harness so as to concentratively form a branch circuit.
A joint block for concentratively accommodating many connectors is provided, and the electric wires to be connected with each other are taken out from an electric wire bundle of a wire harness so as to form a branching circuit connected by the connector of the above described joint block. When the above case is compared with a case where the branch line is branched in accordance with each of the above described devices, the connecting operation can be collectively effected, with an advantage that an engagement operation of the whole wire harness becomes extremely easy.
In a wire harness with electric wires being bundled, it has considerable weight, and also, considerable space is necessary for the arrangement of the wire harness.
Because of the concentration of the connectors and the concentration of branch positions from the wire harness, a considerably unreasonable design may be required in the branching circuit design of the wire harness.
For example, the joint block is made large in size so as to concentratively accommodate the connectors, so that the mounting position of the joint block is restricted.
When the joint block is mounted on the car body, various restrictions are present with respect to the available space. When the space restrictions are due to the size of the joint block itself, the mounting position is extremely restricted. The joint block mounting position may be a considerable distance away from the arrangement position of the electric wiring parts to be connected with the branching circuit of the joint block, and also, the take-out position of the branch electric wire group from the wire harness main line may be a considerable distance away from the above described joint block mounting position.
In the above described case, the extra electric wires have to be used. The diameter of the wire harness has to be increased correspondingly, thus increasing the weight and cost. Further, the shape of the wire harness becomes complicated to lower the efficiency of the assembling operationality.
When the branch circuit is constructed with the joint block as described hereinabove, the circuit within the branch connector is difficult to change.
In a case of a device using the above described bus bar, it is necessary to change the arrangement of the terminals for connecting the electric wires. In a case of composing a circuit with the above described pressure contact terminals it is necessary to change the pressure contact terminals. It takes more time to pull out and replace the terminals or pressure contact terminals once mounted on a case. It is extremely difficult practically in terms of cost and so on.